Internal Error: Sub-system: HDB, File: /quartus/db/hdb/hdb_syn_iname.cpp, Line: 472 - Internal Error: Sub-system: HDB, File: /quartus/db/hdb/hdb_syn_iname.cpp, Line: 472 Description Due to a problem in the Intel® Quartus® Prime Pro Edition software version 18.0 update 1 and earlier, you may see this error at Analysis and Synthesis stage when you use a special character '~' for the pin name. Resolution To work around this problem, remove the special character '~' in the pin name. This problem is fixed beginning with the Intel® Quartus® Prime Pro Edition software version 18.1 Custom Fields values: ['novalue'] Troubleshooting 2205677024 False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] 18.1 18.0.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']